Methods and apparatus for processing a substrate

ABSTRACT

A method of cleaning an edge of a substrate is provided. The method comprises tensioning a first polishing film in a frame; contacting the first polishing film against an edge of a substrate; conforming the first polishing film to the edge of the substrate, the edge including an outer edge and at least one bevel; and rotating the substrate while the first polishing film remains in contact with the substrate. Numerous other aspects are provided.

This application is a division of, and claims priority to, U.S.Non-Provisional patent application Ser. No. 11/299,295, filed Dec. 9,2005, and titled, “METHODS AND APPARATUS FOR PROCESSING A SUBSTRATE”(Attorney Docket No. 10121), which is hereby incorporated by referenceherein in its entirety for all purposes.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention is related to U.S. patent application Ser. No.11/298,555 filed on Dec. 9, 2005 and entitled “METHODS AND APPARATUS FORPROCESSING A SUBSTRATE” (Attorney Docket No. 10414) which is herebyincorporated herein by reference for all purposes.

FIELD OF THE INVENTION

The present invention relates generally to substrate processing, andmore particularly to methods and apparatus for cleaning an edge of asubstrate.

BACKGROUND

Conventional systems, which contact a substrate edge with an abrasivefilm to clean the edge, may not thoroughly clean the edge. For example,the abrasive film may not sufficiently contact both bevels of the edgeduring cleaning. Additionally, the abrasive film may become worn fromuse, and therefore, lose its ability to sufficiently clean the substrateand require frequent replacement, which may affect semiconductor devicemanufacturing throughput. Accordingly improved methods and apparatus forcleaning an edge of a substrate are desired.

SUMMARY OF THE INVENTION

In a first aspect of the invention, an apparatus adapted to polish anedge of a substrate includes a polishing film, a frame adapted totension the polishing film so that at least a portion of the film issupported in a plane, and a substrate rotation driver adapted to rotatea substrate against the plane of the polishing film such that thepolishing film is adapted to apply tension to the substrate, contour toan edge of the substrate which includes at least an outer edge and afirst bevel, and polish the outer edge and the first bevel as thesubstrate is rotated.

In a second aspect of the invention an apparatus adapted to polish anedge of a substrate includes a plurality of polishing films, a frameadapted to tension each of the polishing films so that at least aportion of each of the films are supported in a respective plane, and asubstrate rotation driver adapted to rotate a substrate against at leastone of the respective planes of the polishing films such that anypolishing films contacting the substrate apply pressure to thesubstrate, contour to an edge of the substrate, and polish the edge asthe substrate is rotated.

In a third aspect of the invention an apparatus adapted to polish anedge of a substrate includes a polishing film having a polishing sideand a second side, an inflatable pad disposed adjacent the second sideof the polishing film, a frame adapted to support the polishing film andthe inflatable pad, and a substrate rotation driver adapted to rotate asubstrate against the polishing side of the polishing film. Thepolishing film is disposed between an edge of the substrate and theinflatable pad so that the inflatable pad and polishing film contour tothe edge of the substrate and the polishing film contacts the edge ofthe substrate.

In a fourth aspect of the invention a method of cleaning an edge of asubstrate includes (a) supporting a polishing film, (b) conforming thepolishing film to an edge of a substrate, the edge including an outeredge and at least one bevel, and (c) rotating the substrate.

Other features and aspects of the present invention will become morefully apparent from the following detailed description, the appendedclaims and the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic illustration of a cross-section of a portion of asubstrate.

FIG. 2 is a schematic illustration depicting an example embodiment of anedge cleaning apparatus according to the present invention.

FIGS. 3A and 3B are close-up front and side cross-sectional schematicviews, respectively, of a portion of the edge cleaning apparatus of FIG.2.

FIG. 4 is a perspective view depicting an example embodiment of an edgecleaning apparatus according to the present invention.

FIG. 5 is a perspective view depicting another example embodiment of anedge cleaning apparatus according to the present invention.

FIG. 6 is a perspective view of a portion of the example embodimentdepicted in FIG. 5.

FIGS. 7A and 7B are close-up perspective views of different embodimentsof replaceable cassettes for use with embodiments of the presentinvention.

FIGS. 8A through 8C are close-up perspective views of differentembodiments of pads for use with embodiments of the present invention.

FIGS. 9A through 9C are plan views of examples of different possiblehead positions of the example edge polishing apparatus of FIG. 4.

FIGS. 10A through 10C are plan views of examples of different possiblehead positions of the example edge polishing apparatus of FIG. 5.

FIG. 11 is a perspective view of an embodiment of a multiple head edgepolishing apparatus according to the present invention.

FIG. 12 is a perspective view of another embodiment of a multiple headedge polishing apparatus according to the present invention.

FIG. 13 is a perspective view of yet another embodiment of a multiplehead edge polishing apparatus according to the present invention.

DETAILED DESCRIPTION

The present invention provides improved methods and apparatus forcleaning and/or polishing the edge of a substrate. With reference toFIG. 1, a substrate 100 may include two major surfaces 102, 102′ and anedge 104. Each major surface 102, 102′ of the substrate 100 may includea device region 106, 106′ and an exclusion region 108, 108′. (Typicallyhowever, only one of the two major surfaces 102, 102′ will include adevice region and an exclusion region.) The exclusion regions 108, 108′may serve as buffers between the device regions 106, 106′ and the edge104. The edge 104 of a substrate 100 may include an outer edge 110 andbevels 112, 114. The bevels 112, 114 may be located between the outeredge 110 and the exclusion regions 108, 108′ of the two major surfaces102, 102′. The present invention is adapted to clean and/or polish theouter edge 110 and at least one bevel 112, 114 of a substrate 100without affecting the device regions 106, 106′. In some embodiments, allor part of the exclusion regions 108, 108′ may be cleaned or polished aswell.

The present invention provides a frame for supporting a film (e.g., anabrasive polishing film) or abrasive buffer against the edge 104 of asubstrate 100 as the substrate 100 is rotated (e.g., by a vacuum chuck,drive rollers, etc.). The film may be pressed against the rotatingsubstrate edge 104 using a pad pushed by an actuator and/or aninflatable pad. In either case, the pad and/or inflatable pad may besoft and/or include or develop contours to conform with the shape of thesubstrate edge 104. Depending on the amount of force applied by theactuator, the resiliency of the pad selected, the amount of inflation ofan inflatable pad, and/or the amount of tension on the film, acontrolled amount of pressure may be applied to polish the edge 104.Alternatively or additionally, the film may be under tension within theframe such that the film itself is adapted to apply a variable amount oftension to the substrate edge 104 and to contour to both the outer edge110 and at least one of the bevels 112, 114 (e.g., with or withoutadditional support from a pad). Thus, the present invention providesprecise control of an edge polish process which may be used tocompensate for different edge geometries and changes in the substrate100 as material is removed from the edge 104.

In some embodiments, the frame may support multiple heads, each headbeing adapted to support polishing film. The heads may support differenttypes of films (e.g., films of different abrasive grits) which may beused concurrently, in a predefined sequence, or at different times. Theheads may be disposed in different positions to allow the supportedfilms to polish different portions of the edge 104 of the rotatingsubstrate 100. The heads may be adapted to be moved (e.g., angularlytranslated about a tangential axis of the substrate 100 and/orcircumferentially relative to the substrate 100) around the edge 104 bythe frame so as to polish different portions of the edge 104. In someembodiments, the heads may continuously oscillate around the rotatingedge 104 of the substrate 100. Each head may include an indexed spool offilm and/or be contained in a replaceable cassette.

Additionally or alternatively, the present invention may includefacilities to deliver fluids to the substrate edge 104 being polished.In some embodiments, one or more channels may be provided to directchemicals or water to the substrate edge 104 to assist in the polishingand/or to wash away particles resulting from the polishing. Thechemicals may be sprayed directly onto the substrate 100, at thesubstrate/polishing film interface, and/or may be applied to and/orthrough the film and/or pad. The fluids may be sprayed from either orboth sides of the substrate 100 and the present invention may employgravity or suction to cause the runoff not to contaminate or contactother parts of the substrate 100 or apparatus of the invention. Further,energy (e.g., megasonic energy) may be applied to the substrate edge 104via fluid carrying such energy.

The substrate 100 may be rotated in a horizontal plane. In additional oralternative embodiments, the substrate 100 may be rotated in a verticalplane, other non-horizontal plane, and/or be moved between differentplanes of rotation.

Turning to FIG. 2, a schematic view of an edge polishing apparatus 200is depicted. A frame 202 supports and tensions a polishing film 204 in aplane perpendicular to the major surfaces 102, 102′ of a substrate 100such that the edge 104 of the substrate 100 may be pressed against(e.g., as indicated by the straight downward arrows 205 a, 205 b) thepolishing film 204 and the polishing film 204 may contour to thesubstrate edge 104. As indicated by the curved arrow 205 c, thesubstrate 100 may be rotated against the polishing film 204. Thesubstrate 100 may be rotated at a rate ranging from about 50 to 300 RPM,for example, although other rates may be used. The substrate 100 maycontact the polishing film 204 for about 15 to 150 seconds depending onthe type of film used, the grit of the film, the rate of rotation, theamount of polishing required, etc. More or less time may be used. Insome embodiments, the polishing film 204 may be supported by a pad 206disposed adjacent a backside (e.g., a non-abrasive side) of thepolishing film 204 and mounted on the frame 202. As indicated by thestraight upward pointing arrow 207, the frame 202 including thetensioned polishing film 204 and/or the pad 206 may be pushed againstthe edge 104 of the substrate 100. In some embodiments, the substratemay be pushed against the polishing film with an amount of force rangingfrom about 0.5 lbs. to about 2.0 lbs. Other amounts of force may beused.

Additionally or alternatively, an additional length of the polishingfilm 204 may be supported and tensioned by spools 208, 210 mounted tothe frame 202. A supply spool 208 may include unused polishing film 204available to be unwound and pulled into position adjacent the substrate100 while a take-up spool 210 may be adapted to receive used and/or wornpolishing film 204. One or both of the spools 208, 210 may be indexed toprecisely control the amount of polishing film 204 that is advanced. Thepolishing film 204 may be made from many different materials includingaluminum oxide, silicon oxide, silicon carbide, etc. Other materials mayalso be used. In some embodiments, the abrasives used may range fromabout 0.5 microns up to about 3 microns in size although other sizes maybe used. Different widths ranging from about 1 inch to about 1.5 inchesmay be used (although other widths may be used). In one or moreembodiments, the polishing film may be about 0.002 to about 0.02 of aninch thick and be able to withstand about 1 to 5 lbs. of tension inembodiments that use a pad 206 and from about 3 to about 8 lbs. oftension in embodiments without a pad. Other films having differentthicknesses and strengths may be used. The spools 208, 210 may beapproximately 1 inch in diameter, hold about 500 inches of polishingfilm 204, and may be constructed from any practicable materials such aspolyurethane, polyvinyl difloride (PVDF), etc. Other materials may beused. The frame 202 may be constructed from any practicable materialssuch as aluminum, stainless steel, etc.

In some embodiments, one or more fluid channels 212 (e.g., a spraynozzle or bar) may be provided to deliver chemicals and/or water to aidin the polishing/cleaning of the substrate edge 104, lubricate thesubstrate, and/or to wash away removed material. The fluid channel 212may be adapted to deliver fluid to the substrate 100, to the polishingfilm 204, and/or to the pad 206. The fluids may include deionized waterwhich may serve as a lubricant and to flush particles away. A surfactantand/or other known cleaning chemistries may also be included. In someembodiments, sonic (e.g., megasonic) nozzles may be used to deliversonicated fluids to the substrate edge 104 to supplement the cleaning.Fluid also may be delivered through the polishing film 204 and/or pad206 to the edge 104.

Turning to FIGS. 3A and 3B, close-up front and side cross-sectionalschematic views, respectively, of the polishing film 204 and pad 206 ofFIG. 2 are depicted. Note that the forces (indicated by the straightarrows) cause the polishing film 204 and the pad 206 to contour andconform to the edge 104 of the substrate 100. In some embodiments, ifthe substrate 100 was not present, the pad 206 would have a flat surfacewhere the substrate 100 is shown compressing the pad 206. Likewise, ifthe substrate 100 was not present, the polishing film 204 would lie flatand be represented by a straight line in both views.

Turning now to FIGS. 4 and 5, two additional alternative embodiments ofan edge polishing apparatus 400, 500 are depicted. As shown in FIG. 4,an example edge polishing apparatus 400 may include a base or frame 402that includes a head 404 which supports polishing film 204 tensionedbetween spools 208, 210 and further supported by a pad 206. As shown,the pad 206 may by mounted to the head 404 via a biasing device 406(e.g., a spring). The edge polishing apparatus 400 of FIG. 4 also mayinclude one or more drive rollers 408 (two shown) and guide rollers 410(two shown) that are adapted to rotate the edge 104 of the substrate 100against the polishing film 204. The drive rollers 408 may themselveseach be driven by drivers 412 (e.g., motors, gears, belts, chains,etc.).

The drive rollers 408 and guide rollers 410 may include a groove thatallows the rollers 408, 410 alone to support the substrate 100. In someembodiments the groove within the drive rollers 408 may have a diameterof approximately 2.5 inches and the groove within the guide rollers 410may have a diameter of approximately 1 inch. Other dimensions arepossible. The area of the drive rollers 408 in contact with thesubstrate 100 may include texturing or cross-grooves to allow the driverollers 408 to grip the substrate 100. The drive rollers 408 and guiderollers 410 may be constructed from materials such as polyurethane,polyvinyl difloride (PVDF), etc. Other materials may be used.

As shown in FIG. 5, another example edge polishing apparatus 500 mayinclude a base or frame 502 that includes a head 504 which supportspolishing film 204 tensioned between spools 208, 210 and furthersupported by a pad 206. As shown, the pad 206 may by mounted to the head504 via an actuator 506 (e.g., a pneumatic slide, hydraulic ram, servomotor driven pusher, etc.). The edge polishing apparatus 500 of FIG. 5also may include a vacuum chuck 508 coupled to a driver 510 (e.g.,motor, gear, belt, chain, etc.). An advantage of the embodiment depictedin FIG. 5 is that the apparatus 500 does not need to contact the edge104 being polished. Thus, the potential of particles accumulating ondrive rollers and being re-deposited on the edge 104 is eliminated. Theneed to clean rollers also is eliminated. Further, the possibility ofrollers damaging or scratching the edge is also eliminated. By holdingthe substrate in a vacuum chuck, high speed rotation without vibrationmay be achieved.

Turning now to FIGS. 6 through 8B, some details of features of theexample embodiments of FIGS. 4 and 5 are described. Note that featuresfrom the different embodiments may be combined in many differentpracticable ways to serve different design principals or concerns.

FIG. 6 depicts details of the frame 502 including the head 504 of FIG.5. As described above, a head 504 supports polishing film 204 tensionedbetween spools 208, 210. The frame 502 (that includes head 504) may beadapted to be angularly translated (relative to an axis that istangential to the edge 104 of a substrate 100 held in the edge polishingapparatus 500 (FIG. 5)) by a driver 600 (e.g., a servo motor) and pivot602. The angular translation of the frame (and polishing film 204) isdescribed in more detail below with respect to FIGS. 9A through 10C.

Additionally, the spools 208, 210 that are mounted to the head 504, maybe driven by one or more drivers 604 (e.g., servo motors). The drivers604 may provide both an indexing capability to allow a specific amountof unused polishing film 204 to be advanced or continuously fed to thesubstrate edge, and a tensioning capability to allow the polishing filmto be stretched taught and to apply pressure to the substrate edge.

As can more clearly be seen in FIG. 6 (as compared to FIG. 5), theoptional pad 206 may by mounted to the head 504 via an actuator 506 thatis adapted to adjustably press and contour the polishing film 204against a substrate edge 104 (FIG. 5). Further, one or more supportrollers 606 may also be mounted to the head 504 to guide and align thepolishing film 204 in a plane perpendicular to the major surface 102(FIG. 1) of a substrate 100 held in the edge polishing apparatus 500(FIG. 5).

Note that in the embodiment depicted in FIGS. 5 and 6, the length of thepolishing film 204 is disposed orthogonal to the edge 104 of a substrate100 being polished. This is in contrast to the embodiment depicted inFIG. 2, wherein the longitudinal direction of the polishing film 204 isaligned with the edge 104 of a substrate 100 being polished. Otherpolishing film orientations and configurations may be employed. Forexample, the polishing film 204 may be held diagonally relative to themajor surface 102 of the substrate 100.

Turning to FIGS. 7A and 7B, close-up perspective views of two differentembodiments of replaceable cassettes 700A, 700B are depicted. Cassettes700A, 700B may be adapted to provide the features of the head 404 andpolishing film 204 in a disposable, refillable, and/or replaceablepackage which may be quickly and easily mounted on and/or removed fromthe frames 402, 502 of different edge polishing apparatuses 400, 500.

As shown in FIG. 7A, the cassette 700A may include head 404 whichsupports polishing film 204 which spans from supply reel 208 to take-upreel 210. The polishing film 204 may be guided and aligned by supportrollers 606 mounted to the head 404. A pad 206 may be provided tofurther support the polishing film 204 as described above. Also asdescribed above, a biasing device 406 (e.g., a spring) may be employedto mount the pad 206 to the head 404 to provide flexible/dynamiccounter-pressure to the pad 206. Alternatively or additionally, anadjustable actuator 506 (FIG. 6) may be used to push the pad 206 againstthe polishing film 204 or to push the entire head 404 toward thesubstrate 100.

In yet another alternative embodiment, as shown in FIG. 7B, instead of apad 206, the head 404 may simply rely on the tension of the polishingfilm 204 to provide lateral pressure to the substrate edge 104 (FIG. 1).In some embodiments, the head 404 may include a notch 702 as shown inFIG. 7B to accommodate the substrate 100.

Turning to FIGS. 8A and 8B, two different alternative embodiments ofpads 206A, 206B are depicted. In addition to a pad 206 (FIG. 6) that hasa flat surface co-planar with the polishing film 204 when a substrate isnot present, a pad 206A may include a concave surface that matches thecontour of the edge 104 of a substrate 100. Alternatively, as shown inFIG. 8B, the pad 206B may include a double concave surface to bettermatch the contour of the edge 104 of a substrate 100. In yet otheralternative embodiments, a pad 206 may include a shaped groove thatprecisely matches the contour of the edge 104 of a substrate 100including the bevels 112, 114 and outer edge 110 (FIG. 1).

The pads 206, 206A, 206B may be made of material such as, for example,an acetal resin (e.g., Delrin® manufactured by DuPont Corporation),PVDF, polyurethane closed cell foam, silicon rubber, etc. Othermaterials may be used. Such materials may have a resilience or anability to conform that is a function of the thickness or density of thepad. The material may be selected based upon its resilience. The desiredresilience may be selected based upon the type of polishing required.

In some embodiments, the pad 206, 206A, 206B may have an adjustableamount of ability to conform to the substrate's edge. For example thepad 206, 206A, 206B may be or include an inflatable bladder such that byadding more air or liquid or other fluid, the pad becomes harder and byreducing the amount of air or liquid or other fluid in the bladder, thepad becomes more conforming. FIG. 8C depicts an embodiment of a pad 206Cthat includes an inflatable bladder 802 that may be filled (and/oremptied) via a fluid channel 804 with fluid from a fluid supply 806. Insome embodiments, the fluid supply 806 may inflate/deflate the bladder802 under the direction of an operator or a programmed and/or useroperated controller. In such embodiments, an elastomeric material suchas silicon rubber or the like, may be used for the bladder 802 tofurther enhance the pad's ability to stretch and conform to thesubstrate's edge 104. Such an embodiment would allow anoperator/controller to precisely control how far beyond the bevels 112,114 (if at all) and into the exclusion region 108 and/or 108′ (FIG. 1)the polishing film 204 is made to contact the substrate 100 by, e.g.,limiting the amount of fluid pumped into the bladder 802. For example,once a substrate outer edge 110 is placed against a pad 206C with adeflated bladder 802, the bladder 802 may be inflated so that the pad206C is forced to wrap around and conform to the outer edge 110 andbevel(s) 112, 114 of the substrate 100 without wrapping around to thedevice region 106, 106′ of the substrate 100. Note that in someembodiments, multiple bladders may be used in a pad and that differentlyshaped inflatable bladders may be used within differently shaped pads206, 206A, 206B.

In some embodiments, fluids used to aid in the polishing may bedelivered to the substrate edge via the pads 206, 206A, 206B. A fluidchannel may be provided to drip or spray the fluid on or into the pads.Alternatively, an inflatable pad may include a bladder with asemi-permeable membrane that allows fluid to be slowly released andtransmitted to the polishing film 204 (e.g., through the pad). In suchembodiments, the pads 206, 206A, 206B may be covered by, made of, and/orinclude material that absorbs and/or retains the fluids used (e.g.,polyvinyl alcohol (PVA), etc.).

FIGS. 9A through 9C and FIGS. 10A through 10C depict examples ofdifferent possible head positions of the alternative edge polishingapparatuses 400, 500 respectively, described above. The presentinvention is adapted to bring polishing film 204 in contact with thebevels 112, 114, and outer edge 110 of a substrate 100 withoutcontacting the device region 106 of the substrate 100. In operation,this is achieved by angularly translating a head 404, 504 (andconsequently, a portion of polishing film in contact with and contouredto the edge 104 of a substrate 100) around an axis that is tangential tothe outer edge 110 of the substrate 100 as it is rotated. Referring toFIGS. 9A through 9C and FIGS. 10A through 10C, this axis of angulartranslation may be represented by a line extending perpendicular out ofthe paper upon which the FIGs. are drawn at the point labeled “P.” Theheads 404, 504 may be held in various positions to clean desiredportions of the substrate edge 104 as the substrate 100 is rotated. Insome embodiments, the heads 404, 504 may be adapted to continuously orintermittently oscillate between the various positions depicted and/orother positions. The heads 404, 504 may be moved on the frame 502 bydrivers 600 (FIG. 6) under the direction of a programmed or useroperated controller. Alternatively, the heads 404, 504 may be fixedand/or only adjusted while the substrate is not being rotated. In yetother embodiments, the substrate may be held fixed while the heads areoscillated (as described above) as well as rotated circumferentiallyaround the substrate 100. Further, the polishing film 204 may be mountedon the heads 404, 504 in a continuous loop and/or the polishing film 204may be continuously (or intermittently) advanced to polish the substrateedge 104. For example, the advancement of the film may be used to createor enhance the polishing motion. Any combination of the above describedpolishing motions and/or methods that are practicable may be employed.

Turning to FIGS. 11 through 12, additional embodiments of an edgepolishing apparatus are depicted. FIG. 11 depicts an edge polishingapparatus 1100 including three heads 404, FIG. 12 depicts an edgepolishing apparatus 1200 including two heads 504, and FIG. 13 depicts anedge polishing apparatus 1300 including four heads 1304. As suggested bythe drawings, any number and type of heads 404, 504, 1304 may be used inany practicable combination. In addition, in such multi-headembodiments, each head 404, 504, 1304 may used a differently configuredor type of polishing film 204 (e.g., different grits, materials,tensions, pressures, etc.). Any number of heads 404, 504, 1304 may beused concurrently, individually, and/or in a sequence. Different heads404, 504, 1304 may be used for different substrates 100 or differenttypes of substrates. For example, a first head 404 with a stiff biasingdevice 406 supporting a pad 206 such as the concave pad 206B and acoarse grit polishing film 204 may initially be used to remove arelatively large amount of rough material from the substrate bevels 112,114 (FIG. 1). The first head 404 may be appropriately positioned toaccess the bevels 112, 114. After cleaning with the first head 404 iscompleted, the first head 404 may be backed away from the substrate 100,and a second head 504 with a fine grit polishing film 204 (and without apad) may be moved into position to polish the bevels 112, 114 and theouter edge 110.

After cleaning one or more substrates 100, the portion of the polishingfilm 204 employed for such cleaning may become worn. Therefore, thetake-up reel 210 (FIG. 4) may be driven to draw the polishing film 204by a fixed amount from the supply reel 210 (FIG. 4) toward the take-upreel 210. In this manner, an unused portion of the polishing film 204may be provided between the take-up reel 210 and supply reel 208. Theunused portion of the polishing film 204 may be employed to subsequentlyclean one or more other substrates 100 in a manner similar to thatdescribed above. Consequently, the apparatus 1100, 1200 may replace aworn portion of polishing film 204 with an unused portion with little orno impact on substrate processing throughput. Likewise, if replaceablecassettes 700A are employed, impact on throughput may be minimized byquickly replacing the cassettes 700A when all the polishing film 204 inthe cassette 700A is used.

Regarding the example embodiment of an edge polishing apparatus 1300 ofFIG. 13 specifically, a frame 1302 that supports multiple heads 1304 isdepicted in schematic form. The heads 1304 are each mounted to the frame1302 and each include an actuator 1306 (e.g., pneumatic piston, servodriven slide, hydraulic ram, etc.) adapted to press a pad 206 and alength of polishing film 204 against the edge 104 of a substrate 100 inresponse to a control signal from a controller 1308 (e.g., a programmedcomputer, an operator directed valve system, an embedded real timeprocessor, etc.). Note that the controller 1308 is coupled (e.g.,electrically, mechanically, pneumatically, hydraulically, etc.) to eachof the actuators 1306.

In addition, a fluid supply 806 may be coupled to and under the controlof the controller 1308. The fluid supply 806 may be controlled toindependently deliver fluids (e.g., DI water, cleaning chemistry,sonicated fluids, gas, air, etc.) to each of the heads 1304 via one ormore fluid channels 212. Under the direction of the controller 1308,various fluids may be selectively delivered to the pads 206, thepolishing film 204, and/or the substrate edge 104 via the fluid channels212. The fluid may be for use in polishing, lubricating, particleremoval/rinsing, and/or inflating a bladder 802 (FIG. 8C) within thepads 206. For example, in some embodiments, the same fluid deliveredthrough a permeable pad 206 may be used for both polishing and inflatingthe pad 206 while a different fluid, delivered to the same head 1304 viaa second channel (not shown) is used for rinsing and lubricating.

The foregoing description discloses only exemplary embodiments of theinvention. Modifications of the above disclosed apparatus and methodswhich fall within the scope of the invention will be readily apparent tothose of ordinary skill in the art. For instance, although only examplesof cleaning a round substrate are disclosed, the present invention couldbe modified to clean substrates having other shapes (e.g., a glass orpolymer plate for flat panel displays). Further, although processing ofa single substrate by the apparatus is shown above, in some embodiments,the apparatus may process a plurality of substrates concurrently.

Accordingly, while the present invention has been disclosed inconnection with exemplary embodiments thereof, it should be understoodthat other embodiments may fall within the spirit and scope of theinvention, as defined by the following claims.

1. A method of cleaning an edge of a substrate comprising: tensioning afirst polishing film in a frame; contacting the first polishing filmagainst an edge of a substrate; conforming the first polishing film tothe edge of the substrate, the edge including an outer edge and at leastone bevel; and rotating the substrate while the first polishing filmremains in contact with the substrate.
 2. The method of claim 1 furthercomprising: delivering a fluid to the edge of the substrate.
 3. Themethod of claim 2 wherein delivering the fluid further comprises:applying at least one of water and a cleaning chemistry to the edge ofthe substrate via an inflatable pad.
 4. The method of claim 2 whereindelivering the fluid further comprises: applying at least one of waterand a cleaning chemistry to the edge of the substrate via the firstpolishing film.
 5. The method of claim 1 further comprising: conforminga second polishing film to the edge of the substrate.
 6. The method ofclaim 5 wherein the second polishing film includes a different type ofpolishing film compared to the first polishing film.
 7. The method ofclaim 6 wherein the first and second polishing films contact the edge ofthe substrate one of sequentially and simultaneously.
 8. The method ofclaim 1 further comprising: delivering fluid including sonic energy tothe edge of the substrate.
 9. The method of claim 1 further comprising:rotating the substrate for between 5 and 150 seconds.
 10. The method ofclaim 1 wherein the frame includes one or more heads adapted to conformthe first polishing film to the edge of the substrate.
 11. The method ofclaim 10 further comprising: angularly translating the one or more headsand the first polishing film around an axis tangential to the outer edgeof the substrate.
 12. The method of claim 10 further comprising:circumferentially rotating, with respect to the substrate, the one ormore heads around the edge of the substrate.
 13. The method of claim 1further comprising: advancing the first polishing film as it contactsthe substrate edge.
 14. The method of claim 10 wherein conforming thefirst polishing film further comprises: pressing a conformable padportion of the head against the first polishing film.
 15. The method ofclaim 14 further comprising: adjusting the pressure applied by theconformable pad against the first polishing film.
 16. The method ofclaim 15, wherein the pressure is adjusted by a controller based on asignal.
 17. The method of claim 10 further comprising: oscillating theone or more heads between positions that allow the first polishing filmto contact at least one bevel and the outer edge of the substrate. 18.The method of claim 10 further comprising: controlling the movement ofthe one or more heads with a controller.
 19. The method of claim 10further comprising: polishing a predefined portion of the edge of thesubstrate with the one or more heads.
 20. The method of claim 1 furthercomprising: moving the edge of the substrate in a longitudinaldirection; and spanning the first polishing film between a supply spooland a take up spool in a longitudinal direction.